Die cast battery cup and anvil



July 20, 1965 D. s. FOOTE ETAL DIE CAST BATTERY CUP AND ANVIL Filed July 19, 1962 6 m M OMUEM O m wmm m wwzmwbaw mmm w a 1 MWMKPM S 3 mm w pm KW H M w Mm Q. WWLN. LIIO G 4 M H 2 w Q.

United States Patent 3,195,463 DIE CAST BATTERY CUP AND ANVlL Donald S. Foote, Greens Farms, Theodore B. Johnson,

Strattord, Richard A. Sahlin, Fairlield, and Justin H.

Whipple, Milford, Conn, assignors to Remington Arms Company, Inc., Bridgeport, Conn., a corporation of Delaware Filed .luly 19, 1962, Ser. No. 211,004 4 Claims. (Cl. 1tl286.5)

This invention relates to a hermetically sealed primer for use in setting off another explosive charge which, while effectively sealing the priming mixture, also is effective in its principal function of setting off the main explosive charge.

More specifically, the present invention relates to a primer in which the sensitive priming mixture is hermetically sealed by using an integral body and anvil assembly which efiectively seals the priming mixture and at the same time has thin membrane portions which are blown out with the pressure of the exploding gas so that flash holes are formed by which the flame of the ignited priming mixture is carried to the main propellant charge in the cartridge.

The advantages of providing hermetically sealed primers are known in the art since various attempts have been made in the past to produce this type of primer.

The present invention has these general advantages and some other advantages unique to the present construction. First, by providing a unitary die cast battery cup and anvil, there will be a material cost reduction. Secondly, a reduced number of manufacturing operations will re- Sult by combining anvil, battery cup and assembly operations into a single die casting. Further, closed flash holes will eliminate explosives from dusting out of the primer as well as eliminate static electricity hazards and mass detonation in the event that a battery cup and anvil is set off by any possible source. Bulk packing of primers for interplant and commercial shipping will be possible because of the non-mass detonating characteristics of the present invention. Another advantage is that the closed flash holes permit the use of fine grain propellant powders without these powders shifting into the battery cup and causing primer cups to set back on firing. Another advantage is that the closed flash holes confine primer explosion before the membrane breaks away to increase the efiiciency of the primer.

A further advantage of the modification shown in FIGS. and 6 is that the practice of using foil paper to contain the priming mixture in the primer cup is eliminated and the anvil itself used as the tamping punch. Moreover, the separate anvil and charged cup assembly operation is eliminated since it is combined with the charging operation. Finally, in military applications, where the primer is subject to high G forces, the anvil design supports the priming mixture and prevents its falling out.

It is an object of this invention to provide a hermetically sealed primer which is eflective to set otf a main explosive charge.

It is another object of this invention to provide a unitary die cast battery cup and anvil.

It is another object of this invention to provide a primer body member having weakened portions therein which are adapted to blow out upon firing of the primer to form flash holes.

Other objects will be apparent from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a cross-sectional elevation view of the preferred embodiment.

3,195,453 Patented July 20, 1965 FIG. 2 is a plan view of the unitary battery and anvil assembly.

FIG. 3 is a sectional view of the preferred unitary battery and anvil assembly.

FIG. 4 is a view taken on line 4-4 of FIG. 1.

FIG. 5 is a cross-sectional elevational view of another embodiment of the invention.

FIG. 6 is a plan view of the primer shown in FIG. 5.

Referring now to the drawings on which like reference numerals are employed to designate like parts throughout the several views, a primer indicated generally by numeral 10 comprises a tubular casing 12 having an outwardly projecting circular flange 14 at its outer end and an inwardly projecting flange 16 located intermediate the inner and outer ends of the casing 12. Inner end portion 18 is bevelled or inclined at its outer face Ztl in order to facilitate insertion of the primer in an opening in the cartridge (not shown).

Integral with and connecting the circular inner peripheral edges 22 of the flange 16 is a dome-shaped member 24 on which is integrally mounted a substantially flat triangular anvil member 26. (See FIG. 3.) Anvil member 26 also is integral with the upper face 28 of flange 16. (See FIG. 1.) Flange 16 is thus, in effect, a support means for the anvil 26 and dome 24. It can be seen that a unitary member consisting of casing 12,

flange 16, dome 24, and anvil is formed which can readily be made by die-casting methods.

It should be appreciated that the dome configuration of member 24 is not merely for aesthetic purposes. The structural advantages of a dome over a flat member are well known. In this particular instance, it was necessary to provide a strong support for the anvil and at the same time to provide a thin membrane with sufficient exposure area which would blow out upon ignition of the priming mixture.

A second advantage of the dome configuration is that better ignition characteristics are achieved by having the hot, incandescent gases from the priming mixture come through the inner end of the battery cup as a single, hot, jet to ignite the propellant powder instead of as two or more separate flames, thus, eliminating turbulence, etc. It should be realized that although the explosion does blow out the weakened portions 30 and 32, the angularlydirected, separate flames coming through these portions combine within the dome (see FIGURE 3) and leaves the orifice bottom of the dome as a single jet to ignite the propellant powder more efliciently.

As can be seen in FIG. 3, dome member 24 includes segments 3% and 32 which connect flange face 22 and anvil 26. These segments (FIGS. 2 and 3) are made of thin Sections which are designed to blow out when the primer is exploded. The thickness of membranes 30 and 32 depend on various factors including the thickness and weight of the battery cup as well as manufacturing limitations. However, an average segment will have a thickness of approximately 0.0030.004 inch. Upon blowing out of the segments, flash holes are formed which permit the flame of the exploding priming mixture to travel therethrough in order to set oif the main explosive or propellant in the cartridge or shell.

Inserted in the open end of the casing 12 is a primer cup assembly 34 comprising an open-end cylindrical casing 36 in which sensitive priming mixture 38 is securely positioned by any well-known means, e.g., a foil 40 adapted to hold the priming material in place. The primer cup assembly 34 is forced into the open end of the casing 36 by press fit or other means to prevent re moval thereof and also to prevent dust or moisture from entering the pocket or chamber 42 formed by the casing 12 and the primer cup assembly 34.

It can be seen from FIG. 1 that the anvil end 44 is axially spaced from the primer cup assembly 34 so that when the bight portion 46 of the primer cup casing is impacted, the priming mixture 38 will be caused to strike anvil end 44 and explode. The resultant increase in gas pressure will blow out segments 30 and 32 thus forming flash holes through which the flame escapes.

The above modification is designed especially for shotshell primers whereas the modification shown in FIGS. 5 and 6 is designed for centerfire shells.

The modification of FIGS. 5 and 6 shows a primer cup 48 comprising an open-end cylindrical casing 55) having a bight portion 50a and a unitary body member 52 inserted into the open end of the casing 50 by a press fit in order to define a hermetically sealed chamber or pocket 54. Positioned within said sealed chamber is priming mixture 56. The unitary body member 52 comprises a continuous flange portion 52a and an integral support member 52b connected thereto. integrally formed on said body support member 52b and. projecting into the sealed chamber 54 is an anvil member 58. During the assemblying operation of the primer, the priming mixture is first placed in casing 50 and the body member 52 and anvil 58 moved down to temp the mixture in place and seal the mixture in the chamber 54.

As can be seen in FIG. 5, the body member 52 includes thin membrane segments 60 and 62 which are integral with the body support member 52b and the continuous flange portion 52a and are designed to blow out upon firing of the priming mixture 56 to form flash holes for reasons mentioned above. An average membrane in this modification will have a thickness in the vicinity of 0.006 inch. It can be seen that the continuous flange portion 52a, the support member 5212, and the thin segments 60 and 62 form an inner bight portion which corresponds to the bight portion 50a of the outer primer cup.

It should be appreciated that various modifications can be made using the inventive concept explained herein. Thus, the idea of a hermetically sealed primer having thin membrane walls which are designed to be blown out can also be utilized without an anvil means. One such possibility would be an electrically fired primer. It is to be understood that the invention in its broader aspects can be utilized in various other means and that the scope of the invention is to be determined by the appended claims.

What is claimed is:

1. In a cartridge having a head end adapted to receive a primer in a conventional manner, said primer comprising an integrally formed, unitary-battery cup and anvil insertable in said cartridge head, said unitary battery cup and anvil comprising a tubular casing having a continuous flange means integral with and projecting inwardly from the inner wall of the forward portion of said casing, an elongated anvil integral with said flange means and projecting rearwardly towards an open end of said casing, a plurality of weakened wall portions integral with said flange means and said anvil thus providing an integral, imperforate closure for the forward end of said casing, and a primer cup means having priming material mounted therein positioned to close off the open end of said battery cup and to space the priming material a desired distance from the end of the anvil, said weakened wall portions adapted to be blown out by the explosive priming material gases upon ignition, said weakened wall portions comprising curved wall portions of predetermined thickness which, when taken together with a curved bottom portion of said anvil form a hemispherical dome.

2. A primer adapted to be loaded and assembled independently of and inserted in the head end of a cartridge, said primer comprising a primer cup having a iii A solid, imperforate end wall and an open end, a onepiece, integrally formed, unitary body and anvil assembly mounted in sealing relationship with said primer cup and defining a hermetically sealed chamber therebetween in which a sensitive priming mixture is positioned, said body and anvil assembly comprising a tubular casing having support means integral therewith from which an integral anvil extends into said hermetically sealed chamher, and weakened portions, integral with said support means, which together with said support means forms an integral imperforate end closure of said body casing and which is in continuous supporting relationship with said priming mixture thus preventing movement of said priming mixture within said hermetically sealed chamber, said weakened portions being adapted to be ruptured to form flash holes upon firing of said priming mixture.

3. A primer adapted to be loaded and assembled independently of and inserted in the head end of a cartridge, said primer comprising an outer cup-shaped casing having a bight portion and a continuous flange portion, an inner body member of one-piece construction having a bight portion and a continuous flange telescoping into said outer casing so that said outer continuous flange portion and said inner continuous flange portion are in sealing relationship with each other, said outer bight portion and said inner bight portion forming a hermetically sealed pocket therebetween, explosive priming means confined in and filling the entire hermetically sealed pocket, said inner body member further comprising a support member integral with said inner continuous flange portion, a plurality of thin-walled section integrally formed with and of the same material as said inner continuous flange portion and said support member, and an anvil means integrally formed with and of the same material as said support member and extending into said hermetically sealed pocket, said thin-walled sections adapted to blow out to form flash holes upon ignition of said explosive priming means.

4. A primer adapted to be assembled independently of and inserted in the head end of a cartridge, said primer comprising a primer cup, a one-piece body and anvil assembly in sealing engagement with said primer cup to define a hermetically sealed chamber therebetween, said assembly including a tubular body element having an anvil integrally formed of the same material therewith, said anvil projecting into said chamber and spaced a predetermined distance from said primer cup, sensitive priming mixture positioned between said anvil and said primer cup, and weakened portions of said assembly integrally formed with and of the same material as said body and anvil, said weakened portions being of predetermined thickness and adapted to be ruptured to form flash holes upon firing of said priming mixture, said weak. ened portions being angularly positioned relative to one another.

References (Jited by the Examiner UNITED STATES PATENTS 158,532 3/74 White 10245 572,888 12/96 Gardner 10245 1,438,779 12/22 Olin 102-45 1,541,437 6/25 Schauerte et al.

2,021,498 11/35 Campbell 102-45 2,868,128 1/59 Ramsey 102-86.5

FOREIGN PATENTS 300,734 11/28 Great Britain. 1,024,404 2/58 Germany.

BENJAMIN A. BORCHELT, Primary Examiner. SAMUEL FEINBERG, Examiner. 

1. INA CARTRIDGE HAVING A HEAD END ADAPTED TORECEIVE A PRIMER IN A CONVENTIONAL MANNER, SAID PRIMER COMPRISING AN INTEGRALLY FORMED, UNITARY BATTERY CUP AND ANVIL INSERTABLE IN SAID CARTRIDGE HEAD, SAID UNITARY BATTERY CUP AND ANVIL COMPRISING A TUBULAR CASING HAVING A CONTINUOUS FLANGE MEANS INTEGRAL WITH AND PROJECTING INWARDLY FROM THE INNR WALL OF THE FORWARD PORTION OF SAID CASING, AN ELONGATED ANVIL INTEGRAL WITH SAID FLANGE MEANS AND PROJECTING REARWARDLY TOWARDS AN OPEN END OF SAID CASING, A PLURALITY OF WEAKENED WALL PORTIONS INTEGRAL WITH SAID FLANGE MEANS AND SAID ANVIL THUS PROVIDING AN INTEGRAL, IMPERFORATE CLOSURE FOR THE FORWARD END OF SAID CASING, AND A PRIMER CUP MEANS HAVING PRIMING MATERIAL MOUNTED THEREIN POSITIONED TO CLOSE OFF THE OPEN END OF SAID BATTERY CUP AND TO SPACE THE PRIMING MATERIAL A DESIRED DISTANCE FROM THE END OF THE ANVIL, SAID WEAKENDED WALL PORTIONS ADAPTED TO BE BLOWN OUT BY THE EXPLOSIVE PRIMING MATERIAL GASES USPON IGNITION, SAID WEAKENED WALL PORTIONS COMPRISING CURVED WALL PORTIONS OF PREDETERMINED THICKNESS WHICH, WHEN TAKEN TOGETHER WITH A CURVED BOTTOM PORTION OF SAID ANVIL FORM A HEMISPHERCAL DOME. 